Faradaic electrochemical impedance spectroscopy for enhanced analyte detection in diagnostics

Electrochemical impedance spectroscopy (EIS) is a widely implementable technique that can be applied to many fields, ranging from disease detection to environmental monitoring. EIS as a biosensing tool allows detection of a broad range of target analytes in point-of-care (POC) and continuous applications. The technique is highly suitable for multimarker detection due to its ability to produce specific frequency responses depending on the target analyte and molecular recognition element (MRE) combination. EIS biosensor development has shown promising results for the medical industry in terms of diagnosis and prognosis for various biomarkers. EIS sensors offer a cost-efficient system and rapid detection times using minimal amounts of sample volumes, while simultaneously not disturbing the sample being studied due to low amplitude perturbations. These properties make the technique highly sensitive and specific. This paper presents a review of EIS biosensing advancements and introduces different detection techniques and MREs. Additionally, EIS's underlying theory and potential surface modification techniques are presented to further demonstrate the technique's ability to produce stable, specific, and sensitive biosensors.